The present invention relates to an antigen-antibody complex and a method of using the same as an agglutination reagent.
One of the conventional reagents for use in testing the Rh blood type is a monoclonal human anti-D antibody (hereinafter "monoclonal human anti-D"). The production and the use of this monoclonal human anti-D are described in the Proceedings of the 13th Japanese society for Immunology (1983), pp. 416-417, and Japanese Patent Application Kokai Nos. 58-500,366, 59-138,959, and 60-70,361. Another reagent is a polyclonal human anti-D obtained from the human serum. This is a commonly used, officially licensed reagent.
However, the reactivity of the above monoclonal antibody with the corresponding antigen is so low that the antibody is useful for only a few testing methods. For the Rh blood typing, for example, these are an anti-human globulin testing method, a bromelain solution method, an albumin solution method, and a physiological saline solution method. The monoclonal human anti-D presented in the 13th Japanese Society for Immunology is able to cause agglutination by the anti-human globulin testing or bromelain solution method and determined the blood type of an Ph(D) antigen but unable to cause any agglutination by the albumin or saline solution method, thus putting a limit on its applicability.
The polyclonal human anti-D antibody is a human origin reagent using human serum or its dilution with a proper diluent and it is difficult to produce it in large amounts because the human serum is obtained usually by administering Rh negative persons with the Rh positive blood.